#include "aes.h"

static const uint32_t rcon[10] = {
    0x01000000UL, 0x02000000UL, 0x04000000UL, 0x08000000UL, 0x10000000UL,
    0x20000000UL, 0x40000000UL, 0x80000000UL, 0x1B000000UL, 0x36000000UL};

uint8_t S[256] = {
    0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
    0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
    0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
    0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
    0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
    0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
    0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
    0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
    0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
    0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
    0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
    0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
    0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
    0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
    0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
    0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16};

uint8_t inv_S[256] = {
    0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
    0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
    0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
    0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
    0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
    0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
    0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
    0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
    0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
    0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
    0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
    0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
    0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
    0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
    0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
    0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D};

void LoadStateArray(uint8_t (*State)[4], const uint8_t *pDataIn)
{
  for (uint8_t i = 0; i < 4; ++i)
  {
    for (int j = 0; j < 4; ++j)
    {
      State[j][i] = *pDataIn++;
    }
  }
}

void StoreStateArray(uint8_t (*pDataIn)[4], uint8_t *pDataOut)
{
  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      *pDataOut++ = pDataIn[j][i];
    }
  }
}

bool KeyExpansion(const uint8_t *pKeyIn, uint32_t KeyLen, AesKey *AesKey)
{
  if ((pKeyIn == NULL) || (AesKey == NULL) && (KeyLen != 16))
    return false;

  uint32_t *w = AesKey->eK;
  uint32_t *v = AesKey->dK;

  for (uint8_t i = 0; i < 4; ++i)
  {
    LOAD32H(w[i], pKeyIn + 4 * i);
  }

  for (int i = 0; i < 10; ++i)
  {
    w[4] = w[0] ^ MIX(w[3]) ^ rcon[i];
    w[5] = w[1] ^ w[4];
    w[6] = w[2] ^ w[5];
    w[7] = w[3] ^ w[6];
    w += 4;
  }

  w = AesKey->eK + 44 - 4;
  for (uint8_t j = 0; j < 11; ++j)
  {

    for (uint8_t i = 0; i < 4; ++i)
    {
      v[i] = w[i];
    }

    w -= 4;
    v += 4;
  }

  return true;
}

void AddRoundKey(uint8_t (*State)[4], const uint32_t *pKeyIn)
{
  uint8_t k[4][4] = {0};

  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      k[i][j] = (uint8_t)BYTE(pKeyIn[j], 3 - i);
      State[i][j] ^= k[i][j];
    }
  }
}

void SubBytes(uint8_t (*State)[4])
{
  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      State[i][j] = S[State[i][j]];
    }
  }
}

void InvSubBytes(uint8_t (*State)[4])
{
  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      State[i][j] = inv_S[State[i][j]];
    }
  }
}

void ShiftRows(uint8_t (*State)[4])
{
  uint32_t Block[4] = {0};

  for (uint8_t i = 0; i < 4; ++i)
  {
    LOAD32H(Block[i], State[i]);
    Block[i] = ROF32(Block[i], 8 * i);
    STORE32H(Block[i], State[i]);
  }
}

void InvShiftRows(uint8_t (*State)[4])
{
  uint32_t Block[4] = {0};

  for (uint8_t i = 0; i < 4; ++i)
  {
    LOAD32H(Block[i], State[i]);
    Block[i] = ROR32(Block[i], 8 * i);
    STORE32H(Block[i], State[i]);
  }
}

uint8_t GMul(uint8_t u, uint8_t v)
{
  uint8_t p = 0;

  for (uint8_t i = 0; i < 8; ++i)
  {
    if (u & 0x01)
    {
      p ^= v;
    }

    uint8_t Flag = (v & 0x80);
    v <<= 1;
    if (Flag)
    {
      v ^= 0x1B;
    }

    u >>= 1;
  }

  return p;
}

void MixColumns(uint8_t (*State)[4])
{
  uint8_t Tmp[4][4] = {0};
  uint8_t M[4][4] = {{0x02, 0x03, 0x01, 0x01},
                     {0x01, 0x02, 0x03, 0x01},
                     {0x01, 0x01, 0x02, 0x03},
                     {0x03, 0x01, 0x01, 0x02}};

  for (uint8_t i = 0; i < 4; ++i)
  {
    for (int j = 0; j < 4; ++j)
    {
      Tmp[i][j] = State[i][j];
    }
  }

  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      State[i][j] = GMul(M[i][0], Tmp[0][j]) ^ GMul(M[i][1], Tmp[1][j]) ^ GMul(M[i][2], Tmp[2][j]) ^ GMul(M[i][3], Tmp[3][j]);
    }
  }
}

void InvMixColumns(uint8_t (*State)[4])
{
  uint8_t Tmp[4][4] = {0};
  uint8_t M[4][4] = {{0x0E, 0x0B, 0x0D, 0x09},
                     {0x09, 0x0E, 0x0B, 0x0D},
                     {0x0D, 0x09, 0x0E, 0x0B},
                     {0x0B, 0x0D, 0x09, 0x0E}};

  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      Tmp[i][j] = State[i][j];
    }
  }

  for (uint8_t i = 0; i < 4; ++i)
  {
    for (uint8_t j = 0; j < 4; ++j)
    {
      State[i][j] = GMul(M[i][0], Tmp[0][j]) ^ GMul(M[i][1], Tmp[1][j]) ^ GMul(M[i][2], Tmp[2][j]) ^ GMul(M[i][3], Tmp[3][j]);
    }
  }
}

bool AesEcbEncrypt(const uint8_t *pKeyValue, uint32_t KeyLen, const uint8_t *pDataIn, uint8_t *pDataOut, uint32_t DataSize)
{
  AesKey AesKey = {0};
  uint8_t *pos = pDataOut;
  uint8_t State[4][4] = {0};
  uint8_t ActualKey[16] = {0};
  uint8_t out[BLOCKSIZE] = {0};
  const uint32_t *rk = AesKey.eK;

  if ((pKeyValue == NULL) || (pDataIn == NULL) || (pDataOut == NULL))
    return false;

  if ((KeyLen > 16) && (DataSize % 16))
    return false;

  memcpy(ActualKey, pKeyValue, KeyLen);
  KeyExpansion(ActualKey, 16, &AesKey);

  for (uint32_t i = 0; i < DataSize; i += BLOCKSIZE)
  {
    LoadStateArray(State, pDataIn);
    AddRoundKey(State, rk);

    for (uint8_t j = 1; j < 10; ++j)
    {
      rk += 4;
      SubBytes(State);
      ShiftRows(State);
      MixColumns(State);
      AddRoundKey(State, rk);
    }

    SubBytes(State);
    ShiftRows(State);
    AddRoundKey(State, rk + 4);

    StoreStateArray(State, pos);

    pos += BLOCKSIZE;
    pDataIn += BLOCKSIZE;
    rk = AesKey.eK;
  }

  return true;
}

bool AesEcbDecrypt(const uint8_t *pKeyValue, uint32_t KeyLen, const uint8_t *pDataIn, uint8_t *pDataOut, uint32_t DataSize)
{
  AesKey AesKey;
  uint8_t *pos = pDataOut;
  uint8_t State[4][4] = {0};
  uint8_t ActualKey[16] = {0};
  uint8_t out[BLOCKSIZE] = {0};
  const uint32_t *rk = AesKey.dK;

  if ((pKeyValue == NULL) || (pDataIn == NULL) || (pDataOut == NULL))
    return false;

  if ((KeyLen > 16) && (DataSize % 16))
    return false;

  memcpy(ActualKey, pKeyValue, KeyLen);
  KeyExpansion(ActualKey, 16, &AesKey);

  for (int i = 0; i < DataSize; i += BLOCKSIZE)
  {
    LoadStateArray(State, pDataIn);
    AddRoundKey(State, rk);

    for (int j = 1; j < 10; ++j)
    {
      rk += 4;
      InvShiftRows(State);
      InvSubBytes(State);
      AddRoundKey(State, rk);
      InvMixColumns(State);
    }

    InvSubBytes(State);
    InvShiftRows(State);
    AddRoundKey(State, rk + 4);

    StoreStateArray(State, pos);
    pos += BLOCKSIZE;
    pDataIn += BLOCKSIZE;
    rk = AesKey.dK;
  }

  return true;
}
